Prescription Electronics - COB ( Clean Octave Blend )  [traced]

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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby rousejeremy » 11 Jun 2009, 16:25

here's the vero

Image

Does this match the schematic above?
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Jonah-S » 11 Nov 2009, 10:19

Same thing here...just hissing.
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Jonah-S » 11 Nov 2009, 22:20

Okay, the one thing I missed (which probably is REALLY obvious to others) :roll: , is that according to the diagram, Blend 2 should be connected to Volume 3. This helped somewhat, but all I get now is a very very VERY slight sound out of the box. It IS making an upper octave/octavio effect, but my amp has to be crancked in order for me to hear anything... :scratch:
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Jonah-S » 12 Nov 2009, 21:11

Nope, not getting it working....Gonna breadboard it just to see what it should sound like, and that all of my components are in working order... it would sure be nice to get a verification on the VERO...
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Skinpimp » 14 Nov 2009, 09:35

needs another trace cut to the left of emitter of Q2 .
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Jonah-S » 15 Nov 2009, 18:46

....aaaand it's verified! Thank's skinpimp!
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby patafix » 15 Nov 2009, 20:47

Does it make a sound now ? Any tester here ?
Patafix... so sticky
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Jonah-S » 16 Nov 2009, 09:24

Yeah it does! A great sound, very versatile, takes other pedals well, and it's dead quiet! I may try out other trannies just for the heck of it, but it probably won't change much. It's a good one!
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Brink » 19 Nov 2009, 07:50

I just made one, with the extra vero cut, and it's extremely quiet with no octave. Looking at the vero it strikes me that the vero transistors are oriented backwards from the way the standard 3904 TO-92 pinout says they should be.
Can anyone else comment on that?
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Jonah-S » 19 Nov 2009, 09:25

I thought they were backwards as well. After double checking, the emitters are in fact connected to the ground rail as should (via R4, R7, R12 and R17). To test out different possibilities, I installed transistor sockets, and ended up aligning the trannies as shown in the vero layout. Everything works fine. I can post soundclips and pics later, if needed for comparison.

-Jonah
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Brink » 22 Nov 2009, 00:21

Jonah-S wrote:I thought they were backwards as well. After double checking, the emitters are in fact connected to the ground rail as should (via R4, R7, R12 and R17). To test out different possibilities, I installed transistor sockets, and ended up aligning the trannies as shown in the vero layout. Everything works fine. I can post soundclips and pics later, if needed for comparison.

-Jonah

Please do post sound clips, I'll see if I can too.

I switched all 4 trannies around (the opposite of what is shown in the vero) and the circuit works now.
It's not a totally clean sound, kind of a splat thing going on and some compression as well as chords get very muddy, but it works and I kind of like the sound.
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby Jonah-S » 23 Nov 2009, 17:50

I don't think it's possible to get a whammy type digitally "clean sound" out of an analog device. As I'm sure you already know, a little fuzz is allways needed to produce an upper octave. I've found many usable settings, but mostly I turn the blend knob almost all the way. It seems that in order to get an approximate 50/50 ratio in the cleanest octave setting, the pot has to be turned about three quarters up. With the octave/fuzz knob turned up halfway, the blend knob can be proportionately turned down to get a satisfactory mix...
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby OnTheTundra » 29 Oct 2011, 18:24

I used 2n3903 transistors and it wouldn't work until I flipped the first two. Once I did that it makes a great octavio/green ringer-ish upper octave. I think I'll add a boost behind it in the box and then it'll be great.
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby rosetta » 31 Oct 2011, 03:39

Hi guys, have u chacked the same project on DIYSB??? welll to all those how doesn't here is the link and they have a PCB verified.

http://www.diystompboxes.com/smfforum/i ... c=77090.20
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby brejna » 26 Aug 2016, 17:40

Hey guys, do you have schematic for COB? I cannot find it..

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Re: Prescription Electronics - COB ( Clean Octave Blend )  [traced]

Postby turdadactyl » 16 Jan 2017, 23:53

brejna wrote:Hey guys, do you have schematic for COB? I cannot find it..

Cheers


Not my work. Found it online.

Prescription Electronics-COB Clean Octave Blend.jpg
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brejna (17 Jan 2017, 18:02), modman (20 Mar 2017, 22:33)
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Re: Prescription Electronics - COB ( Clean Octave Blend )

Postby ThiagoFaraday » 16 Mar 2017, 00:06

I'm having problems with mounting this schematic above, I can not seem to find the errors
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